Rotary offset press



July 28, 1936. A. s. MacLAREN 0 ROTARY OFFSET PRESS I 4. -S. M4 cAez/v INVENTOR:

ATTORNEY,

July 28, 1936. s ac A 2,048,801

ROTARY OFFSET PRESS Filed June 30, 1933 5 Sheets-Sheet 2 min A 6'. M4 cl 2125A ATTORNEY INVENTOR:

July 28, 1936. MacLAREN 2,048,801

ROTARY OFFSET PRESS Filed June 30, 1933 I 5 Sheets-Sheet 3 U- k INVENTQR as. Mid/12m ATTORNEY July 28, 1936. s, MacLAREN ROTARY OFFSET PRESS Filed June 30, 1933.

5 Sheets-Sheet 4 lNVENTOR ,4. S. Mal/ 251? QMQM ATTO RN EY July 28, 1936- A. s. MacLAREN 2,048,801

I ROTARY OFFSET PRESS Filed,June 30, 1933 5 Sheets-Sheet 5 INVENTOR ATTORNEY 4; 5. MACZAREA/ Patented July 28, 1936 UNITED STATES PATENT OFFICE ROTARY OFFSET PRESS Albert S. MacLaren, Omaha, Nebr. Application June 30, 1933, Serial No. 678,453

4 Claims.

My invention relates to printing mechanism, and particularly to printing by rolling contact, and wherein the impression from the primary printing member or plate is received on an inter- 5 mediate member from which it is transferred or oflset onto the paper or other material to be printed. It is the object of my invention to provide a rotary offset printing press adapted for high-speed operation on separate sheets of paper or the like, and wherein the material printed may move in a plane tangent to the rolling impression members, without bending to conform with the curvature of such members. A further object of my invention is to provide a rotary offset printing 15 mechanism adapted for the printing of stiff sheets of material such that the same would be injured by bending to conformity with the curvature of a small cylinder. A further object of my invention is to provide printing mechanism of the de- 20 scribed class, wherein feeding and register of the printing stock is effected without the use of grippers or other reciprocating operating elements which limit the speed of operation of the mechanism. A further object of my invention is to 25 provide a press of the described class adapted for use with photo-engraved plates as the primary printing member, and with which ordinary wet plates or deep-etched dry plates may be used optionally. Fin-ther and more particular objects 3a of my invention will be set forth hereinafter.

In the accompanying drawings Fig. 1 is a plan view of a mechanism embodying my invention, Fig. 2 is a longitudinal vertical section on the line 22 of Fig. 1, Fig. 3 is a detail partial side 35 view of one of the drive-gears for the cylinders, Fig. 4 is a detail side view of a portion of the sheet-feeding means, Fig. 5 is a detail section on the line 5-5 of Fig. 4, Fig. 6 is a transverse vertical section, substantially on line 6-6 of Fig. 2,

40 Fig. 7 is a partial left side elevation, showing details of the drive-gearing, Fig. 8 is a detail vertical section on the line 8-8 of Fig. 6, Fig. 9 is a partial right side elevation, Fig. 10 is a detail section on the line ill-l of Fig. 6, and Fig. 11 is a detail 45 .vertical section on the line ll-ll of Fig. 6.

In carrying out my invention according to the illustrated embodiment thereof, 1 provide a sup-.

porting frame having a main vertical portion comprising transversely spaced, inwardly flanged 50 standards ii of which the upper ends are rigidly connected by cross-bars i6. Secured at the inner sides of said standards l are upper and lower horizontal longitudinal frame-members I1 and I8 which extend rearwardly to the legs 2|, the rear 65 ends of said members I1 and It being rigidly conarranged in superposed relation between the 5 standards l5 of the main frame-portion, the cylinder-shafts extending through openings in the standards and being journaled in boxes 28 mounted on angle-brackets 29 on the flat outer sides of,the standards, as best shown in Fig. 6. The rear portions of the brackets supporting the boxes for the upper shaft 21, are connected pivotally with the standards l5, and the front portions of said brackets are connected by links 30 with short crank-arms 3| on the ends of a rocking-shaft 32 mounted in the upper portions of the standards l5. Springs 33, connected with the lower ends of the links 30 as best shown in Figs.

'7, 8 and 9, normally hold the cylinder 26 down into contact with the cylinder 23. A handle 34 on the rocking-shaft 32 is movable to the position indicated by dotted lines in Fig. 8, to raise the links 30 and lift the cylinder 24 out of engagement with the cylinder 23.

Extending transversely between the upper longitudinal frame-members H are cross-bars 35,v beneath which are arranged the longitudinally extending guides 36 having channelled adjoining sides adapted to receive the longitudinal edges of flat sheets 31 lying in a horizontal plane, and

to direct said sheets between the cylinders 22 and 23, of which the contacting sides are in line with the guide-channels. The guides 36 are adjustable transverseiy, along the cross-bars by which they are supported, to accommodate sheets 35 of different widths. For actuating the sheets 31 along the guides 36, there are provided a pair of endless chainsv38 having thereon lugs 39 adapted to engage the rear edges of the sheets and push the same forwardly. Said chains 38 extend 40 about sprocket-wheels 40 and 4| carried respectively by front and rear transverse shafts 42 and 43 journaled in suitable boxes M on the framemembers ll. The upper sides of said chains, extending between the upper parts of the sprocket- 45 wheels, are in horizontal register with the guides 36 and serve to support the intermediate portions of the sheets 31 while impelling the same along the guides. Said upper portions of the chains are kept taut by idler-sprockets 45 engaged with the lower portions of the chains and carried by a floating-shaft 46. Said shaft 46 is carried by swinging arms 41 pivoted on a cross-shaft 48 on the frame-members II, and the floating-shaft 46 is pulled yieldingly downward by a spring 49 constructure shown, the press is driven by an electric motor 5| mounted on a base 52 secured to the front portion of the longitudinal frame-member l1 at the right side of the frame. From the drivepulley. 53 of said motor, a belt 69 extends to a pulley 55 secured on the end of the shaft 26. At the opposite or left side of the frame, intermeshing gears 56, 51 and 58 are secured respectively upon the shafts'25, 26 and 21, whereby the shafts 25 and 21 are driven from the shaft 26. Each of said gears 56, 51 and 58, is preferably formed in two parts which are relatively movable circumferentially to slightly ofiset the portions of the teeth formed thereon, and thus enable compensating adjustments to be made: for taking up any play or back-leash between the gears, whereby to assure rotation of the cylinders 22, 23 and 24 in perfect register with each other. Screws 59, extending loosely through slots in the outer portions of the gears, as shown in Fig. 3, and entering threaded openings therefor in the inner portions, are employed for retaining the parts in adjusted relations. On the end of the shaft 25, at the right side of the frame, is a sprocket-wheel 60 from which a chain 6| extends to a similar sprocket-wheel 62 on the shaft 42, whereby said shaft and the feed-chains 38 aredriven, the driving mechanism being so proportioned and related that advance of the feed-chains is synchronized with the peripheral speed of the cylinders 22 and 23, and the lugs 39 being spaced on the feedchains at distances corresponding to the travel. thereof during one revolution of the cylinders.

The sheets 31 may be fed by hand onto the guides 36, in a position to be engaged and actuated by the lugs 39 of the feed-chains, but ordinarily, for sheets which are flexible, it is preferable to employ an automatic sheet-separating feedmechanism of the type illustrated in Figs. 1 and 2. In said mechanism there is employed a feedtable 63 having its front portion pivotally connected with a fixed shaft 66 extending transversely between the frame-members l1 rearwardly of the shaft 43. Said table 63 is supported at ad- 7 J'usted inclined positions by means of a crankrod 65 engaged selectively with notches in an angle-plate 66 on the lower side of the table, and the table carries side-pieces 61 between which a pile of the sheets 31 may be disposed. Adjacent to the lower front edge of the table 63 is a feedwheel 68, carried upon a transverse shaft 69 journaled in boxes 10 on the frame-members l1, said shaft 69 being driven from the shaft 43 by inter-, meshing gears 1| and 12 secured upon the respective shafts. Adjoining the front edge of the table 63 is a foot-plate 13 which is mounted tiltably on the shaft 6|, said plate 13 having a cushioned face 18 which is held in adjusted relations to the feed-wheel 68 by means of a screw 15 carried by a fixed arm 16 on the shaft 64. Directly beneath the feed-wheel 68 is disposed a small pressure-roller 11 which is carried between the rear portions of a pair of fiat arms 18 pivoted intermediate their ends on a cross-bar 19 arranged directly-beneath the rear. cross-bar 35 on which the guides 36 are carried. A spring 89 connects the front ends of the arms 18 with the floating-shaft 46, the tension of said spring causing the roller 11 to press up yieldingly toward the feed-wheel. The arrangement of the foot-plate 13 is such that the cushioned upper face 18 of said plate engages the lower edges of the inclined pile of sheets 31 which are disposed upon the table 63 in a combed" or feathered" arrangement, whereby the uppermost sheet of the pile is caused to slide by gravity into contact with the feedwheel, and to be impelled by the rotation of said wheel, into a position at which the forward edge of 5 the sheet enters the apex. of the wedge-shaped space between the wheel and foot-plate. On one part of the periphery of the feed-wheel are slightly projecting pads 8l-of rubber or the like which, during their movement past the foot-plate, engage the upper sheet 31 and impel the same forwardly until it is engaged between the wheel and the pressure-roller 11, and the. latter then deliver the sheet into the guides 36, the timed relationof the pads and feed-chain lugs 39 being such that as each sheet is delivered into the guides said lugs are in position to engage the rear edge of the sheet and push it forwardly along the guides.

Each of the cylinders 22, 23, and 24, has a 1ongitudinal slot in which are arranged suitable 20 clamping and tensioning means (not shown) for holding the ends of the packing 82 on the cylinder 22, the offset blanket 83 on the cylinder 23, and the photo-engraved plate 84 on the cylinder 24. Adjacent to the front side of the cylinder 2 23 is a transverse rod 85 to which are slidably connected the front ends of thin fiat guide-bars 86, which extend back beneath the cylinder 23 adjoining the edgesof the blanket 83, as shown in Fig. 6. The width of said blanket is preferably 30 no greater than the width of the form or design to be offset, so that the longitudinal edges or margins of the sheets 31, while passing between the cylinders, may extend beyond the edges of the blanket for engagement with the guide-bars 86, 35 and the sheets be thereby stripped from, or prevented from adhering to the blanket. As the impressed sheets emerge from the cylinders,the stripper or guide-bars 86 direct the same between the delivery-rollers 81 and 88. Said rollers are journaled in brackets 89 secured to and extending forwardly from one of the upper cross-bars l6 and a lower cross-bar 90, extending transversely between the standards 15 of the main frame. The upper roller 81 is driven frictionally from the lower roller 88, and the latter is driven by a pulley 91 secured upon one end of its shaft, which is extended through the bracket 89, said pulley 9| being connected by a belt 92 with a pulley 93 on the shaft 25, between the standard I5 and end of the cylinder 22. From the delivery-rollers the sheets are discharged into a suitable receiver 94 carried upon the forwardly extending portions .of the lower longitudinal frame-members l8.

The brackets 89 support an inking mechanism, comprising an ink-fountain 95, fountain-roller 96, transfer-roller 91, distributing-rollers 98, 99, 100, IM and l02,-and form-rollers 103 and I114. The shaft 99' of the roller 98 is extended through the 60 right-hand bracket 89 and carries a pulley I05 I which is driven by a belt I06 from a pulley I01 011' tended through the brackets 89 and carry grooved wheels III which areoperatively engaged by an 70 inclined cam-disk H2 arranged between them. Said cam-disk is carried by a shaft H3 journaled in a standard 4 mounted on the adjacent forwardly extending portion of the longitudinal frame-member l1. The shaft 3 carries a pulley I I5 and is driven by a belt I I6 connecting said pulley and the shaft 21. Rotation of the shaft and cam-disk H2 causes longitudinal oscillation of the rollers 98 and I00 in opposite directions, to effect lon itudinal distribution of the ink received upon the roller 98 from the transfer-roller 91. The shaft 91' of said transfer-roller extends through arcuate slots in the brackets 89 and is journaled in swingable links H1 of which the lower ends are connected to each other by a crossrod H8, also extending through arcuate slots in the brackets 89. A cam H9 on the shaft H3 actuates a bar I20, connected with the shaft 91, to swing the links I I 1 and engage theroller 91 alternately with the fountain-roller 96 and distributing-roller 98. tain-roller is extended to carry a ratchet-wheel I2I and a swinging pawl-arm I22 having a pawl I23 for engaging said wheel. The pawl-arm is actuated by a link I24 which connects the arm with a crank I25 on the outer end of the shaft To the upper cross-bar I6 at the rear side of the, standards I5 are secured brackets I26, between which is carried a water-pan I21 having a roller I28 arranged to dip therein. The shaft I28 of said roller is extended to carry a ratchetwheel I29 and a swinging pawl-arm I30 having a pawl I3I for engaging said wheel. The pawl-arm is connected by a bar I32 with a crank-pin I33 on the hub of the gear 58, whereby the arm is oscillated to intermittently actuate the roller I28. A transfer-roller I34 is carried by swinging arms I35 pivoted on the brackets I26 and connected to each other by a rod I31 parallel with the roller. One end of the rod I31 is extended through an arcuate slot I38 in the adjoining bracket, as best shown in Fig. 11, and on said end of the rod is a cam-roller I39. A cam I40 is carried on a shaft I having a pulley I42 which is driven by belt I43 from the cylinder-shaft 21, and said cam I40 engages the roller I39 to swing the transfer-roller I34 into alternate engagement with the pan-roller I28 and a water-distributing roller I44. The shaft I44 of the latter roller is journaled in the brackets I26, and one end of the shaft is extended to carry a pulley I45 which is driven by a belt I46 from a pulley I41 on the shaft 21, as best shown in Fig. 6. A plate-moistening roller I48 is mounted on swinging arms I49 pivoted on tie-bars I50 extending between the frame cross-bars IS. The upper ends of the arms I49 are connected to each other by a rod I5I, to which is connected a spring I52, the tension of said spring tending to swing the arms I49 about their pivotal axis and press the roller I48 into yielding engagement with the roller I44 and the plate-cylinder 24. The arrangement is such that moisture is conveyed successively from the pan I21 to the roller I28, to the transfer-roller I34, to the distributing-roller I44, to the roller I48, and to the plate 84 on the cylinder 24.

When the rocking-shaft 32 is operated to lift the cylinder 24 out of contact with the cylinder 23, the upward movement of said cylinder 24 swings the roller I48 out of engagement with the roller I44, and prevents the supplying of additional moisture to the plate 84. The upward movement of the cylinder 24 also disengages the same from the lower inking-roller I04. For disengaging the upper inking-roller I 03 from the cylinder, the shaft I03 of said roller is journaled eccentrically in bushings I53 which are rotatable to move the roller out of engagement with the cylinder when the latter is in raised position, as

The shaft 96' of the founshown by dotted lines in Fig. 10. The bushings I53 have radially extending pins I54 which are engaged and actuated by fingers I55 carried on arms I56 secured on the rocking-shaft 32, the arrangement being such that the eccentric bush- 5 ings are actuated by the same movement of the rocking-shaft which serves to raise the cylinder.

For use with deep-etched or dry photo-engrave'd plates, the water-supplying and distributing devices may be omitted, or made inoperative by the removal of the plate-moistening roller I48.

The general operation of the press will be obvious from the foregoing, and it will be seen that the mechanism is adapted for high-speed operation in the printing of relatively small sheets of paper or the like, or for printing sheets of stiff material which are incapable of bending, or which would be injured by bending the same to conformity with a small cylinder. By the use of continuously moving pushing means for feeding the sheet to the impression-cylinder, the use of gripper or other reciprocating parts is avoided, and it is also made possible for the sheets to pass through between the cylinders along a rectilinear path, and without bending to conform with the curvature of the cylinders, as would be necessary if grippers were employed.

Now, having described my invention, what I claim and desire to secure by Letters Patent is:

1. In combination, a rotary offset press including an impression-cylinder and an oifsetcylinder arranged in superposed relation, a packing on the impression-cylinder, an offset-blanket on the offset-cylinder, said packing and blanket each having a longitudinal slot therein, means for rotating said cylinders in synchronism so that the respective slots substantially register and meet between the cylinders upon rotation thereof, means synchronized with the cylinders for feeding sheets of paper successively between the cylinders into the slots of the packing and blanket as said slots meet upon rotation of said cylinders, said cylinders then gripping said paper between the packing and offset blanket upon further rotation thereof, and means for stripping finished sheets from the cylinders.

2. In combination, a rotary offset press having an offset-cylinder and an impression cylinder arranged in superposed relation, a packing on the impression-cylinder, an offset blanket on the offset-cylinder, said packing and blanket each having a longitudinal slot therein, means for rotating said cylinders in synchronism so that the respective slots substantially register and meet between said cylinders upon rotation thereof, means synchronized with said cylinders for registrably feeding a sheet of paper between said cylinders into the slots of the packing and blanket upon each revolution of said cylinders, and means I between the cylinders spaced longitudinally outwardly of the blanket and packing thereof for stripping finished sheets from the offset-cylinder.

3. In combination, a rotary oifset press having an impression-cylinder and an offset-cylinder arranged in superposed relation, a packing on the impression-cylinder, an offset blanket on the offset-cylinder, the circumferential ends of the packing and blanket being spaced apart to provide respective longitudinal slots therein, means for rotating the cylinders in synchronism so that the respective slots substantially register and meet between said cylinders upon rotation thereof, continuously forwardly moving means synchronized with the cylinders for feeding a sheet of paper into the slots of the packing and blanket upon revolution of said cylinders whereby said sheet is gripped between said cylinders upon further rotation thereof, and means for stripping finished sheets from the oflset cylinder.

4. In combination, a rotary ofiset press having an impression-cylinder and an offset-cylinder arranged in superposed relation, a packing on the impression-cylinder, an offset blanket on the offset-cylinder, said packing and blanket each having a longitudinal slot therein, means for rotating said cylinders in synchronism so that the respective slots substantially register with each other and meet between said cylinders upon every revolution thereof, and continuously forwardly moving means synchronized with the cylinders for registrably feeding sheets of paper into the slots of the packing and blanket each time said slots meet, said means comprising an endless sheet-actuating means having projecting pins thereon longitudinally spaced apart a distance substantially equal to the circumference of the cylinders, continuously forwardly moving means for operatively feeding sheets of paper to the endless sheet-actuating means, and means for stripping'flnished sheets from the cylinders.

' ALBERT S. MACLAREN. 

